1. Field of the Invention
The present invention relates generally to card connectors and methods of assembling the same, and particularly to a memory card connector that is incorporated in electronic apparatuses such as digital cameras to allow a memory card to be attached thereto and a method of assembling the memory card connector.
2. Description of the Related Art
Electronic apparatuses such as digital cameras, portable audio apparatuses, cellular phones, and electronic copiers have a memory card connector incorporated therein and are used with a memory card having a built-in semiconductor memory device being attached to the memory card connector.
Currently, there are multiple kinds of memory cards such as Memory Stick (trademark), Memory Stick Duo (trademark), SD Memory Card (trademark), and MMC (MultiMedia Card) (trademark). With commercial availability of multiple kinds of memory cards, memory card connectors have been commercialized that allow selective attachment of any kind of memory card. This type of memory card connector is mounted on a printed circuit board with its lead terminal parts soldered to corresponding pads on the printed circuit board.
Memory card connectors of this type are divided into those having a single memory card insertion slot common to multiple kinds of memory cards and those having an upper memory card insertion slot and a lower memory card insertion slot. The latter memory card connectors have an advantage over the former memory card connectors in that more kinds of memory cards are attachable.
FIG. 1 is a diagram showing a structure of a conventional memory card connector 1 of the latter type.
The memory card connector 1 has the structure where an upper housing 5 in which contact members 6 are provided by insert molding is stacked on and fixed to a lower housing 2 in which contact members 3 are provided by insert molding. The memory card connector 1 is mounted on a printed circuit board 10 with lead terminal parts 3a and 6a thereof being soldered to corresponding pads 10a and 10b, respectively, on the printed circuit board 10. (See, for example, Japanese Laid-Open Patent Application No. 2005-50792.)
In this memory card connector 1 having a two-tier structure, variations in the arrangement of the lead terminal parts 6a of the contact members 6 of the upper housing 5 result from variations in the contact members 6 themselves together with assembly error in attachment of the upper housing 5 onto the lower housing 2. In some cases, the variations increase so that some lead terminal parts 6a may be out of contact with the corresponding pads 10a of the printed circuit board 10 when the memory card connector 1 is mounted on the printed circuit board 10.
Further, as described above, there are multiple kinds of memory cards at present. The method of detecting the attachment (attached state) of a memory card to a memory card connector differs depending on the type of the memory card. One method is to detect the attachment of a memory card through contact of a predetermined one of the terminals of the memory card with a corresponding contact in the memory card connector. The other method is to detect the attachment of a memory card by causing a switch provided in the memory card connector to operate by a side of the memory card pressing the switch. The former method is employed for Memory Stick (trademark) and Memory Stick Duo (trademark), and the latter method is employed for SD Memory Card (trademark) and MMC (MultiMedia Card) (trademark).
FIGS. 2A and 2B are diagrams for illustrating attachment of a memory card to a conventional memory card connector.
FIG. 2A shows a conventional memory card connector 1a without its cover.
Referring to FIG. 2A, an SD memory card 20 has a knob 23 provided in a recess 22 on an X2-side surface 21 thereof to be slidable between a write inhibit (write protect) position P1 and a write enable position P2.
Accordingly, the memory card connector 1a to which the SD memory card 20 is attached has an internal switch for detecting the attached SD memory card 20, which is not graphically illustrated but is usually placed at the bottom (Y1) side of the memory card connector 1a, and an internal switch 9 for detecting the position of the knob 23 of the attached SD memory card 20.
The switch 9 includes a fixed terminal 11 and a movable terminal 12. The movable terminal 12 has a U-shaped part 12a in the middle and a projection part 12b at its Y2 end.
Referring to FIG. 2B, when the SD memory card 20 is inserted into and attached to the memory card connector 1a with its knob 23 being set to the write enable position P2, the movable terminal 12 is bent by having its U-shaped part 12a pressed by the knob 23, so that the projection part 12b comes into contact with the fixed terminal 11 to turn on the switch 10. (See, for example, Japanese Laid-Open Patent Application No. 2001-167844.)
In general, in a switch having a movable terminal and a fixed terminal, a foreign object may be sandwiched between the movable terminal and the fixed terminal to cause poor contact. In the above described switch 9, it is desirable to ensure as long a wiping distance of the projection part 12b rubbing and moving on the surface of the fixed terminal 11 as possible in order to avoid poor contact due to sandwiching of a foreign object between the projection part 12b of the movable terminal 12 and the fixed terminal 11.
In the case of the above-described switch 9, however, the wiping direction is the Y1 direction perpendicular to the X2 direction in which the U-shaped part 12a is pressed, so that the wiping distance is extremely short. Therefore, it is difficult to increase the reliability of the switch 9, that is, the reliability of the memory card connector 1a. 